Device fob amplifying voltage and cubeent



F'. E. NULL DEVICE FOR AMPLIFYING VOLTAGE AND CURRENT Fgb; 21, V1928.

Filed Sept. 24. .1926

INVENTOR f /Vf/LL BY' M V61 ATTORNEYS Patented Feb. 21, 192.8..

UNITED STATES PATENT oEFlcE.

FLY EDISON NULL, .QFUBBANZL ILLINOIS.

DEVICE'FOB AMPLIFYINGIVOLTAGE AND CURRENT.

Application led September 24, 1.826. Serial No. 137,544.

M invention relates to a device for amp ifying voltage and current, andit consists in the combinations, constructions and arrangements hereindescribed and claimed.

An object of my invention is to provide a device, b means of which avery high degree of distortionless voltage and Current amplification maybe obtained by utilizing given voltage to deflect a retarded cathode rayfor the subsequent production of Leon ard rays, by means of which theamplifica.- tion is effected.

A further object of the invention is to provide an apparatus which iscomposed of relativel few parts, and by means of which the amp ificationis effected. v

Other objects 'and advantages will -appear in the followingspecification, and the novel features ofthe invention will beparticularly pointed out in the appended claims.

My invention is illustrated in the accompanying drawings, forming partof this application, in which Figure 1 is a diagrammatic View of theapparatus, and

`Figures 2 and 3 are detailed views showing a perforated plate whichforms a part of the apparatus. l

In carryingl out my invention I provide an envelope 1, forming achamberwhich is preferably `made of glass. The air isexhausted from the chamberso as to produce a good vacuum. At one end of the chamber is anelectrostatic focusing mirror C. In front of this mirror is disposed athoriated tun sten filament F, which forms the source o the cathoderays. At G1. I have shown a grid for the acceleration of a cathode beamand at G2 is a retarding grid for decreasing the velocity ofthe beam.The beam, itself, I have indicated at E. At D1 and D2 are electrostaticdeflecting plates which are connected to the source V1 of the voltage tobe amplified. At G3 is a neutral grid which is at the same potential asthe retarding grid G2 on the opposite side of the deflecting plates. AtG,i I have shown an accelerating grid, by means of which the electronbeam is speeded up for the p'roduction of Leonard rays.

The envelope C', has associated with it an envelope C2 in which asecondary discharge takes place. Between these chambers, and inalignment with the central axis 0f the electron beam, is a window inwhich there is a perforated metal late P covered over with thin metalfoil which is brazed to the surface of the plate so as to render theplate gas-tight, but to permit the producionif Leonard rays in theauxiliary cham In. the latter chamber are second discharge electrodes E1and E2, respectively. The latter is connected to one side of a secondarydischarge battery B, the opposite terminal of which is connected withone terminal where the amplified voltage V2 is to be impressed(4 Theelectrode E, is connected to the other terminal, a blocking condenser XCbeing provided in the circuit. At R I have shown a D. C. shunt.

From the foregoing description of the various parts of the device, theoperation may be more clearl understood. Inorder that a large deflectionof the beam may be produced by very small electrostatic deflectingfields, the cathode beam is produced in a good vacuum so as to preventthe shielding of the beam from the defiecting field by space charge. Tothis end the thoriated tungsten filament F is used as the electronsource. The electrostatic focusing mirror C is for the urpo'se ofconcentrating the rays to form a eam with a cross-section of uniformcurrent density. Since the deflection of an electron stream by anelectrostatic field is inversely proportional to its velocity, greatsensitivity can be obtained by passing the electron stream through aretardin field so as to greatly reduce its velocity be ore passing intothe deflecting field. To this end I make use of the. grid G2 throughwhich the beam is passed.

Since the lateral acceleration produced by the deflecting field betweenthe plates D1 and g5 D2 is En; where X is the electric field, e is thecharge, and m the'mass of the electron,

i and is 1.77X 10" electromagnetic units per gram, it is evident that avery small field will produce a great acceleration and will producelarge deflections if the velocity of the electron beam is reduced sothat the ac- Vpart o foil window of the ionization climber with sucientvelocity to produce Leonard rays. In the osition of zero deflection ofthe beam,

fp the cross-section of the focused beam strikes the wall of theionization chamber and has no useful effect, while the other partstrikes the thin metal foil Window in the wall of the ionization chamberfor the production of Leonard rays. Thus the variation in the magnitudeof the Leonard rays produced is directly roportional to the deflectionof tl1e.catho e beam.

The ionization chamber contains gas under pressure. As an example, I mayuse carbon dioxide gas under pressure of 3.95 mm., although the kind ofgas, as pressure, and )iptential drop between the e ectrodes E, and 2may vary Without departing from the spirit of the invention. Eachnegative ion produced by the Leonard rays produces several thousand moreby ionization, by col' lision, in each cm. of its'path to the anode, andevery new ne ative ion" produced, itself produces several tousand.electrons for each cm. of its path, so that the eifect is very greatlymultiplied and a relatively large current may be produced. The dischargeis still stable and directly proportional to the number of ionsinitially produced by the Leon-ard ra S.

- claim: v

1. In an apparatus for amplifying current or voltage, the combination ofa vacuum tube, a source of cathode rays in said tube, means fordirecting the rays to form a beam of subf stantially uniform currentdensity, means for rctarding the velocity of the beam, means fordeliecting the beam after retardation, means for acceleratinr thedeflected beam, and

means for producing Leonard rays bythe" accelerated portion of the beam.

2. In an apparatus for amplifying current y or voltage, the combinationof a vacuum tube, a source of cathode rays 1n said tube,

means for directing the rays to form a beamof substantially uniformcurrent density,

means for rctarding the velocity of the beam,

means for deiecting the beam after retardation, means for acceleratinthe deiected beam, means for producing eonard rays by the acceleratedortion of the beam, a sec ond discharge c amber associated with the saidirst-named tube for receiving the Leonard rays, and electrodes in saidsecond disu charge tube.

FAY EDISON NULL.v

